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authorJacob Keller <jacob.e.keller@intel.com>2015-04-22 14:40:30 -0700
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2015-07-17 19:59:04 -0700
commiteff3cddc222c88943ff515ae9335687c9e2cbaf6 (patch)
tree75e6facb436fef4dc0c60526894cd65c83532462 /include/uapi
parent0d0578815bac634aef6e64794e7ad2473fc7af44 (diff)
clarify implementation of ethtool's get_ts_info op
This patch adds some clarification about the intended way to implement both SIOCSHWTSTAMP and ethtool's get_ts_info. The HWTSTAMP API has several Rx filters which are very specific, as well as more general filters. The specific filters really only exist to support some broken hardware which can't fully implement the generic filters. This patch adds clarification that it is okay to support the specific filters in SIOCSHWTSTAMP by upscaling them to the generic filters. In addition, update the header for ethtool_ts_info to specify that drivers ought to only report the filters they support without upscaling in this manner. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com> Reviewed-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'include/uapi')
-rw-r--r--include/uapi/linux/ethtool.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index cd67aec187d9..cd1629170103 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1093,6 +1093,11 @@ struct ethtool_sfeatures {
* the 'hwtstamp_tx_types' and 'hwtstamp_rx_filters' enumeration values,
* respectively. For example, if the device supports HWTSTAMP_TX_ON,
* then (1 << HWTSTAMP_TX_ON) in 'tx_types' will be set.
+ *
+ * Drivers should only report the filters they actually support without
+ * upscaling in the SIOCSHWTSTAMP ioctl. If the SIOCSHWSTAMP request for
+ * HWTSTAMP_FILTER_V1_SYNC is supported by HWTSTAMP_FILTER_V1_EVENT, then the
+ * driver should only report HWTSTAMP_FILTER_V1_EVENT in this op.
*/
struct ethtool_ts_info {
__u32 cmd;